The reflection-less "Fiction" by Robert Nozick wraps the book. The piece at first seems to be narrated by a fictional character: indeed, its first sentence is "I am a fictional character." But this character goes on to assert that the reader, too, is a fictional character, and that this piece one fictional character reads and another narrates is, in fact, a work of non-fiction, as are all works — works within this fictional world in which we live, that is. But who, then, wrote (or currently writes) our world?

I'm reminded of the webcomic One Over Zero.